Perpetual motion describes "motion that continues indefinitely without any external source of energy; impossible in practice because of friction."[2] It can also be described as "the motion of a hypothetical machine which, once activated, would run forever unless subject to an external force or to wear".[3] There is a scientific consensus that perpetual motion in an isolated system would violate the first and/or second law of thermodynamics.

Machines which extract energy from seemingly perpetual sources—such as ocean currents—are capable of moving "perpetually" (for as long as that energy source itself endures), but they are not considered to be perpetual motion machines because they are consuming energy from an external source and are not isolated systems (in reality, no system can ever be a fully isolated system). Similarly, machines which comply with both laws of thermodynamics but access energy from obscure sources are sometimes referred to as perpetual motion machines, although they also do not meet the standard criteria for the name.

Despite the fact that successful isolated system perpetual motion devices are physically impossible in terms of the current understanding of the laws of physics, the pursuit of perpetual motion remains popular.

There is a scientific consensus that perpetual motion in an isolated system violates either the first law of thermodynamics, the second law of thermodynamics, or both. The first law of thermodynamics is essentially a statement of conservation of energy. The second law can be phrased in several different ways, the most intuitive of which is that heat flows spontaneously from hotter to colder places; the most well known statement is that entropy tends to increase (see entropy production), or at the least stay the same; another statement is that no heat engine (an engine which produces work while moving heat from a high temperature to a low temperature) can be more efficient than a Carnot heat engine.

In other words:

In any isolated system, one cannot create new energy (first law of thermodynamics)

The output power of heat engines is always smaller than the input heating power. The rest of the energy is removed as heat at ambient temperature. The efficiency (this is the produced power divided by the input heating power) has a maximum, given by the Carnot efficiency. It is always lower than one

The statements 2 and 3 only apply to heat engines. Other types of engines, which convert e.g. mechanical into electromagnetic energy, can, in principle, operate with 100% efficiency.

Machines which comply with both laws of thermodynamics by accessing energy from unconventional sources are sometimes referred to as perpetual motion machines, although they do not meet the standard criteria for the name. By way of example, clocks and other low-power machines, such as Cox's timepiece, have been designed to run on the differences in barometric pressure or temperature between night and day. These machines have a source of energy, albeit one which is not readily apparent so that they only seem to violate the laws of thermodynamics.

Machines which extract energy from seemingly perpetual sources - such as ocean currents - are indeed capable of moving "perpetually" until that energy source runs down. They are not considered to be perpetual motion machines because they are consuming energy from an external source and are not isolated systems.

Classification

One classification of perpetual motion machines refers to the particular law of thermodynamics the machines purport to violate:[4]

A perpetual motion machine of the second kind is a machine which spontaneously converts thermal energy into mechanical work. When the thermal energy is equivalent to the work done, this does not violate the law of conservation of energy. However it does violate the more subtle second law of thermodynamics (see also entropy). The signature of a perpetual motion machine of the second kind is that there is only one heat reservoir involved, which is being spontaneously cooled without involving a transfer of heat to a cooler reservoir. This conversion of heat into useful work, without any side effect, is impossible, according to the second law of thermodynamics.

A more obscure category is a perpetual motion machine of the third kind, usually (but not always)[5] defined as one that completely eliminates friction and other dissipative forces, to maintain motion forever (due to its mass inertia). Third in this case refers solely to the position in the above classification scheme, not the third law of thermodynamics. Although it is impossible to make such a machine,[6][7] as dissipation can never be 100% eliminated in a mechanical system, it is nevertheless possible to get very close to this ideal (see examples in the Low Friction section). Such a machine would not serve as a source of energy but would have utility as a perpetual energy storage device.

Use of the term "impossible" and perpetual motion

The current formulation of the laws of physics (called "The Standard Model") is known to be incomplete. Stating that physical things are absolutely impossible is often considered un-scientific.

"Epistemic impossibility" describes things which absolutely cannot occur within our current formulation of the physical laws. This interpretation of the word "impossible" is what is intended in discussions of the impossibility of perpetual motion in a closed system.[8]

The conservation laws are particularly robust from a mathematical perspective. Noether's theorem, which was proven mathematically in 1915, states that any conservation law can be derived from a corresponding continuous symmetry of the action of a physical system.[9] This means that if the laws of physics (not necessarily the current understanding of them, but the actual laws, which may still be undiscovered) and the various physical constants remain invariant over time — if the laws of the universe are fixed — then the conservation laws must hold. On the other hand, if the conservation laws are invalid, then much of modern physics would be incorrect as well.[10]

Scientific investigations as to whether the laws of physics are invariant over time use telescopes to examine the universe in the distant past to discover, to the limits of our measurements, whether ancient stars were identical to stars today. Combining different measurements such as spectroscopy, direct measurement of the speed of light in the past and similar measurements demonstrates that physics has remained substantially the same, if not identical, for all of observable history spanning billions of years.[11]

The principles of thermodynamics are so well established, both theoretically and experimentally, that proposals for perpetual motion machines are universally met with disbelief on the part of physicists. Any proposed perpetual motion design offers a potentially instructive challenge to physicists: one is almost completely certain that it can't work, so one must explain how it fails to work. The difficulty (and the value) of such an exercise depends on the subtlety of the proposal; the best ones tend to arise from physicists' own thought experiments and often shed light upon certain aspects of physics. So, for example, the thought experiment of a Brownian ratchet as a perpetual motion machine was first discussed by Gabriel Lippmann in 1900 but it was not until 1912 that Marian Smoluchowski gave an adequate explanation for why it cannot work.[12] However, during that twelve year period scientists did not believe that the machine was possible. They were merely unaware of the exact mechanism by which it would inevitably fail.

The law that entropy always increases, holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.

“ One day man will connect his apparatus to the very wheelwork of the universe [...] and the very forces that motivate the planets in their orbits and cause them to rotate will rotate his own machinery. ”

Some common ideas reoccur repeatedly in perpetual motion machine designs. Many ideas that continue to appear today were stated as early as 1670 by John Wilkins, Bishop of Chester and an official of the Royal Society. He outlined three potential sources of power for a perpetual motion machine, "Chymical Extractions", "Magnetical Virtues" and "the Natural Affection of Gravity".[1]

The seemingly mysterious ability of magnets to influence motion at a distance without any apparent energy source has long appealed to inventors. One of the earliest examples of a system using magnets was proposed by Wilkins and has been widely copied since: it consists of a ramp with a magnet at the top, which pulled a metal ball up the ramp. Near the magnet was a small hole that was supposed to allow the ball to drop under the ramp and return to the bottom, where a flap allowed it to return to the top again. The device simply could not work: any magnet strong enough to pull the ball up the ramp would necessarily be too powerful to allow it to drop through the hole. Faced with this problem, more modern versions typically use a series of ramps and magnets, positioned so the ball is to be handed off from one magnet to another as it moves. The problem remains the same.

Gravity also acts at a distance, without an apparent energy source. But to get energy out of a gravitational field (for instance, by dropping a heavy object, producing kinetic energy as it falls) one has to put energy in (for instance, by lifting the object up), and some energy is always dissipated in the process. A typical application of gravity in a perpetual motion machine is Bhaskara's wheel in the 12th century, whose key idea is itself a recurring theme, often called the overbalanced wheel: Moving weights are attached to a wheel in such a way that they fall to a position further from the wheel's center for one half of the wheel's rotation, and closer to the center for the other half. Since weights further from the center apply a greater torque, the result is (or would be, if such a device worked) that the wheel rotates forever.[14] The moving weights may be hammers on pivoted arms, or rolling balls, or mercury in tubes; the principle is the same.

Yet another theoretical machine involves a frictionless environment for motion. This involves the use of diamagnetic or electromagnet levitation to float an object. This is done in a vacuum to eliminate air friction and friction from an axle. The levitated object is then free to rotate around its center of gravity without interference. However, this machine has no practical purpose because the rotated object cannot do any work as work requires the levitated object to cause motion in other objects, bringing friction into the problem. Furthermore, a perfect vacuum is an unattainable goal since both the container and the object itself would slowly vaporize, thereby degrading the vacuum.

To extract work from heat, thus producing a perpetual motion machine of the second kind, the most common approach (dating back at least to Maxwell's demon) is unidirectionality. Only molecules moving fast enough and in the right direction are allowed through the demon's trap door. In a Brownian ratchet, forces tending to turn the ratchet one way are able to do so while forces in the other direction aren't. A diode in a heat bath allows through currents in one direction and not the other. These schemes typically fail in two ways: either maintaining the unidirectionality costs energy (Maxwell's demon needs light to look at all those particles and see what they're doing)[dubious – discuss], or the unidirectionality is an illusion and occasional big violations make up for the frequent small non-violations (the Brownian ratchet will be subject to internal Brownian forces and therefore will sometimes turn the wrong way).

Buoyancy is another frequently-misunderstood phenomenon. Some proposed perpetual-motion machines miss the fact that to push a volume of air down in a fluid takes the same work as to raise a corresponding volume of fluid up against gravity. These types of machines may involve two chambers with pistons, and a mechanism to squeeze the air out of the top chamber into the bottom one, which then becomes buoyant and floats to the top. The squeezing mechanism in these designs would not be able to do enough work to move the air down, or would leave no excess work available to be extracted.

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and then 15,059

Abyssus Abyssum Invocat

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"Be polite, be professional, but have a plan to kill everyone you meet. I come in peace."
Marine General James Mattis

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John Rayne 45

In my limited understanding of physics it just makes more sense to me that all this is best explained by the idea that these objects are interdimensional since they seem to break ALL the rules.

And here as well with the limited knoweldge of the science behind it...

But that's where I'm headed... Another point is time = life>death, meaning even if we had technology to travel vast distances we would have to either suspend life during travel or literally time travel. The vast distances of space cannot be traveled even at the speed of light and get any "real distance" in terms of space distance.

My view of space - with more and more updated images I look at space as limitless. There will be groups of galaxies or universes or whatever they are every farther distance we can take a picture of... So in that case, traveling to the farthest galaxy would take millions of "earth years" (again my exaggerated made up number)

UFOs, more often than not, disappear when observed, suddenly rather than gradually, according to most UFO sighting-reports.

UFOs behave, usually, as waves rather than particles, but they have had substance, seemingly, as trace elements of them have been adequately reported; however, they behave more readily as waves (of light), especially in current times.

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TheMacGuffin 915

So that would be my question: do UFOs manipulate time, space, matter and even perceptions on the quantum level in ways that are far beyond our current knowledge? Or do some of them do that, which would mean they were from a very advanced civilization indeed, many orders of magnitude beyond ours with a radically different culture.

Don't want to tromp on your thread but i'll add that a growing number of Christians believe the Bible refers to an alien visitation when it says that God will send strong delusion on people in the last days. IOW's people are primed for UFO's and aliens so He allows satan to appear as one.... just sayin'

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keithisco 2,875

Don't want to tromp on your thread but i'll add that a growing number of Christians believe the Bible refers to an alien visitation when it says that God will send strong delusion on people in the last days. IOW's people are primed for UFO's and aliens so He allows satan to appear as one.... just sayin'

The people on the Isle of Wight are primed for UFO's and aliens? Satan is actually disguising his/her self as a UFO? Christians a thousand years ago would never have thought this (the Inquisition would have seen to that)

No need to add any Moral Theistic BS to an already "dodgy" thread... Just confuses everyone because it has nothing to do with UFO Propulsion Systems.

There are many proposed propulsion systems already out there, with strong science behind them, that we do not need to rely on Theistic dogma.

Edited October 2, 2012 by keithisco

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TheMacGuffin 915

The people on the Isle of Wight are primed for UFO's and aliens? Satan is actually disguising his/her self as a UFO? Christians a thousand years ago would never have thought this (the Inquisition would have seen to that)

No need to add any Moral Theistic BS to an already "dodgy" thread... Just confuses everyone

You probably say that about all the UFO threads, although I don't regard it as a "dodgy" subject in any way.

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TheMacGuffin 915

Don't want to tromp on your thread but i'll add that a growing number of Christians believe the Bible refers to an alien visitation when it says that God will send strong delusion on people in the last days. IOW's people are primed for UFO's and aliens so He allows satan to appear as one.... just sayin'

If there ever was a Satan at all, or any other "fallen angels", who is to say that they weren't ETs? Anyway, it has little to do with the subject at hand.

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John Rayne 45

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Joseph Campbell - “Life is a mystery to be lived, not a problem to be solved”

I started the thread to see what other's thought. People, not scientist, mathematicians, etc. ... I can read specific info on propulsion technologies online and yeah there are different things in the works but none of them address the vast distance of space or spacetime or whatever.

I am:

1) Curious about UFO's and USO's (technology wise)

2) Curious about who or what is controlling the above mentioned.

3) Curious about our oceans and what all is hidden down there. And propulsion systems for submersibles

4) Curious about space

5) Curious about space exploration

All the satan business is irrelevant but here's my two cents

I believe in GOD, I believe Jesus came and died and rose, I believe in Heaven or "afterlife" and therefore MUST believe in Satan. You wouldn't know anything without it's opposite or it wouldn't need to exist. How would you know something was hot if there wasn't cold and on and on.

Satan is the great deciever and comes in many forms, and if he appears as an Alien then it must serve his purpose. God allows satan to tempt us and wll not put before us anything we cannot handle.

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Uncle Sam 1,115

One idea that is really stuff of science fiction is using gravity to create an bubble around your plane or spaceship to exclude it from the external forces effecting it. Because the craft experiences no external forces during flight, it will obtain absolute Zero G while in any type of atmosphere or no atmosphere it is in at the time. This will allow for sharp turns and speeds not previously obtainable by modern methods, which can explain these impossible maneuvers. Using this method will still leave a wake in its path and experience sonic boom, due to the fact air will always cluster in front of a fast moving object. For space travel, all it takes is altering this bubble to deflect molecules in front of it with the smallest amount of force which allows for unhindered travel through space. Crafts will still have to plot paths that avoid planets, asteroids, and stars unless they have enough power to enter alternative failed universe while they travel at ridiculous speeds.

Propulsion?

As for propulsion, that is something I have no clue of how they could do it. They could either alter space and time around them so they instantly appear on the other side of their destination or stepping out of our universe bypassing all planets, stars, and asteroids in their path. There are other ideas such as teleportation that like Battlestar Galactica, Hyper Space such as Stargate SG-1, or FTL travel like in Star Trek which is called Warp Speed.

I think the most plausible travel is FTL, because it could be possible with protection such as Gravity Bubbles or Shields but they will still have to avoid planets and stars along their path.

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Grand Moff Tarkin 19,247

I like the idea that they can manipulate gravity like magnetic force, so that they can balance it out in order to hover motionless, just like magnets repelling each other, and then perhaps magnify the repulsion so that that's how they can suddenly scoot off at great speed. Perhaps for deep space travel they can use a similar technique, although obviously the gravitational forces would be so much weaker so they'd probably have to have some means of magnifying it.

And yes, the idea of a 'bubble' of vacuum while within atmosphere, perhaps created by repelling air molecules, would solve problems of surface friction. Perhaps somehow they can float in zero G within that bubble.

Of course, if the craft that people see aren't manned, that would solve problems of G force anyway.

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DONTEATUS 3,396

Everything is still prone to the dynamics of our atmosphere! If E.T is running outside our physics then ITs all there Bad ! Like In Good Bad ! Like In Totally awesome Bad to the Bone ! I want one of those Rides !